Ukraine said it struck a Russian air base on Saturday, while Russia continued to attack Ukraine with hundreds of drones overnight as part of a stepped-up bombing campaign that has dashed hopes for a breakthrough in efforts to end the more than 3-year-old war.

Russian air defence units downed six Ukrainian drones headed for Moscow on Sunday, mayor Sergei Sobyanin said.

Ukraine said Saturday it struck a Russian airbase that military officials called a "home base" of some fighter jets.